/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.evaluation;

import proguard.classfile.*;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.evaluation.value.*;

/**
 * This class creates Value instance that correspond to specified constant pool entries.
 *
 * @author Eric Lafortune
 */
public class ConstantValueFactory extends SimplifiedVisitor implements ConstantVisitor {
    protected final ValueFactory valueFactory;

    // Field acting as a parameter for the ConstantVisitor methods.
    protected Value value;

    public ConstantValueFactory(ValueFactory valueFactory) {
        this.valueFactory = valueFactory;
    }

    /**
     * Returns the Value of the constant pool element at the given index.
     */
    public Value constantValue(Clazz clazz, int constantIndex) {
        // Visit the constant pool entry to get its return value.
        clazz.constantPoolEntryAccept(constantIndex, this);

        return value;
    }

    // Implementations for ConstantVisitor.

    public void visitIntegerConstant(Clazz clazz, IntegerConstant integerConstant) {
        value = valueFactory.createIntegerValue(integerConstant.getValue());
    }

    public void visitLongConstant(Clazz clazz, LongConstant longConstant) {
        value = valueFactory.createLongValue(longConstant.getValue());
    }

    public void visitFloatConstant(Clazz clazz, FloatConstant floatConstant) {
        value = valueFactory.createFloatValue(floatConstant.getValue());
    }

    public void visitDoubleConstant(Clazz clazz, DoubleConstant doubleConstant) {
        value = valueFactory.createDoubleValue(doubleConstant.getValue());
    }

    public void visitPrimitiveArrayConstant(Clazz clazz, PrimitiveArrayConstant primitiveArrayConstant) {
        value = valueFactory.createArrayReferenceValue("" + primitiveArrayConstant.getPrimitiveType(), null,
            valueFactory.createIntegerValue(primitiveArrayConstant.getLength()));
    }

    public void visitStringConstant(Clazz clazz, StringConstant stringConstant) {
        value = valueFactory.createReferenceValue(ClassConstants.NAME_JAVA_LANG_STRING,
            stringConstant.javaLangStringClass, false, false);
    }

    public void visitMethodHandleConstant(Clazz clazz, MethodHandleConstant methodHandleConstant) {
        value = valueFactory.createReferenceValue(ClassConstants.NAME_JAVA_LANG_INVOKE_METHOD_HANDLE,
            methodHandleConstant.javaLangInvokeMethodHandleClass, false, false);
    }

    public void visitClassConstant(Clazz clazz, ClassConstant classConstant) {
        value = valueFactory.createReferenceValue(classConstant.getName(clazz), classConstant.referencedClass, false,
            false);
    }

    public void visitMethodTypeConstant(Clazz clazz, MethodTypeConstant methodTypeConstant) {
        value = valueFactory.createReferenceValue(ClassConstants.NAME_JAVA_LANG_INVOKE_METHOD_TYPE,
            methodTypeConstant.javaLangInvokeMethodTypeClass, false, false);
    }
}
